1. Field of the Invention
The present invention is generally related to a compound containing (pentaphenyl)phenyl group, and more particularly to a compound containing (pentaphenyl)phenyl group, used as an organic display material, and its polymeric derivative and a method for forming the same.
2. Description of the Prior Art
Organic light emitting diode displays, also known as organic electroluminescent displays (referred to as “OEL display”) have advantages of self-emitting, quick response time, wide viewing angle, simple fabricating processes, and being flexible. Luminance mechanism of organic electroluminescence is similar to that of inorganic light emitting diodes. Generally, organic light emitting diodes can be divided into two categories: small molecule organic light emitting diodes and polymer organic light emitting diodes. For small molecule organic light emitting diodes, small molecule dyes or pigments are the major compositions. For polymer organic light emitting diodes, conjugated macromolecule organic materials are the major compositions.
For small molecule dyes or pigments, polymeric light emitting materials, hole injection materials, hole transport materials, the common drawback is that the glass transition temperature is too low. Since the OEL device produces excess joule heat during operating for a long period of time, the operating temperature of the device generally exceeds the Tg of the material so as to cause the material to recrystallize and thereby to result in brightness decay and shortened lifetime. In light of the above background, it is necessary to develop a novel material for organic light emitting diodes so as to provide an excellent product with good thermal stability, high luminance efficiency, and being unlikely to crystallize. Therefore, the utilization lifetime can be prolonged and the luminance efficiency can be increased.